Method of forming ornamental strip metal



May 28,1940. D. A. MARSHALL I METHDD 0F FORMING ORNAMENTAL STRIP METALoriginal Filed July 22, 19:57

3 Sheets-Sheet 1 Shaw May 28, 1940.

D. A. MARSHALL METHOD 0F FORMING ORNAMENTAL STRIP METAL original Filed#July 22. 1937 3 sheets-sheet 2 .EN y. f .u s, www E uw w V KNAWv wm :IIll n www ww l Nw lnk q. uw Nw w\\ No, Nw 2mb um Kw N, Nn a .R. Mn www@mw. f u mw w May 28, 1940. D. A. MARSHALL METHOD oF FORMING ORNAMENTAL,STRIP METAL slsheets-shet s original Filed July 22. 1937 Snuentor Manja/mM. QN

Patented May 28, 1940 UNITED STATES PATENT OFFiCE METHOD OF FORMINGORNAMENTAL STRIP IWETAL Original application `luly 22, 1937, Serial No.154,992. Divided and this application October 3, 1938, Serial No.233,043

8 Claims.

This invention relates to the method of treating and etc-hing acontinuous metallic strip.

This application is a division of my co-pen'ding application Serial No.154,992 for Method of and means for forming ornamental strip metal, ledJuly 22, 1937.

It is an object of the present invention to provide a new and improvedmethod of etching a continuous metallic strip in an efficient andcommercially practical manner.

Other objects of the invention will become apparent from the -followingdescription taken in connection with the accompanying drawings in which-Figure l is a diagrammatical view of apparatus for carrying out mymethod;

Fig. 2 is a side elevational View of an etching apparatus; l

Fig. 3 is a'sectional view of the etching appa- 20 ratus;

Fig, 4 is a sectional view of the etching apparatus taken along the lineand in the direction of the arrows 4 4 of Fig. 2;

Fig. 5 is a sectional view of spraying appara-tus;

25 Fig. 6 is a view partly in elevation and partly in section of anapparatus for removing exc-ess powdered acid resist from the metallicstrip under treatment;

Fig. '7 is a view partly in elevation and partly 30 in lsection ofapparatus for applying a liquid" acid resist to the metallic strip;

Fig. 8 is a detail view of a part of thel apparatus of Fig. '7; n

Fig. 9 is a View in side elevation of a. heater and associatedstructure, and

Fig. l0 is an end view-of the heater.

In the drawings, the numeral I designates a strip of metal, and in Fig.l, the strip is shown extending between a pair of rolls 2 and 3. The tworolls 2 and 3 are formed of a resilient material, such as hard rubber,and are mounted for rotation about parallel axes. ported in a framestructure 4 by a shaft 5 and the roller 2 is supported by a shaft 6mounted in The roller 3 is .sup-

vertically adjustable elements l, one of which ing a drum printingplaten or cylinder l5, and a freely rotatable backing roll i6 whichengages the bottom of the strip I to press it into contact with theprinting cylinder. The printing cylinder preferably comprises a metalcylinder having a rubber printing plate I'I thereon, the rubber platebeing cemented to the surface of the cylinder and having the desireddesign on its exposed surface. The printing cylinder is supported invertically slidable, removable elements I8, one of which is shown inFig. 1, and screws, such as the one shown at I9, are provided to adjustthe elements I8 vertically.

In using the present apparatus to provide de` signs of different lengthsit is necessary to change the printing cylinders and the inventionprovides for inking of the diiTerent sized cylinders. This apparatuscomprises an ink tray supported for horizontal movement. The rolls 2|and 22` receive ink from the tray 20 and from the roll 22 the ink may betransferred to the printing plate I 'I by a movable roll 23.

The tackiness of the ink employed in some cases is sufficient to permitthe printing cylinder I5 to be driven solely by contact with the stripI. It has been found that the design transferred to the strip when theprinting cylinder is so driven under certain circumstances is quitesharp and clear, whereas in othercases it is desirable to drive theprinting cylinder positively in synchronism with the movement. of theVstrip, as here shown. Further, such contact drive for the printingcylinder permits interchange of cylinders of various diameters withoutthe necessity of interchanging a driving mechanism therefor as well.However, in the present apparatus, it is desirable that the printingcylinder be driven from the rolls 2 and 3, in absolute synchronism withthe `movement of thevstrip I.

The ink used in the present apparatus contains a quantity of animal fat,suchas tallow, and will not dry. It remains-in .a wet, sticky conditionand the powdered asphaltum, with which the strip is subsequentlytreated, readily adheres thereto.

The strip I extends from the yprinting apparatus, above described,beneath a hopper 24 con-- taining powdered asphaltum 25. A verticallyadlll except the inked portions which require the acid resist.

The brushing apparatus, as shown more parF ticularly in Fig. 6,comprises a housing 2l' having a sloped bottom for collecting the excessasphaltum. The strip i in passing through the housing 51 slides over awire screen 29, and mounted above the screen 29, in vertically adejustable supports 35, are sprockets 3i having endless chains 32 thereonsupporting the brushes 33. The brushes 33 are preferably formed ofcamels hair and are propelled across the strip i when the chains aredriven by the motor 34., shown only in Fig. l.

After passing the brushing apparatus the strip l extends to theapparatus for coating the reverse side and the side edges `with an acidresist. As shown more particularly in Fig. '2, this resist coatingapparatus comprises a tank contain ing a quantity of asphaltum held insolution by a solvent such as gasoline. Rotatably supported invertically adjustable elements 35 are rolls 31,

the rolls being so supported that they dip into the liquid asphalturn.The rolls 3l are formed of a comparatively soft brous material, such asfelt, and peripherally grooved disks 38 are mounted by adjustablesupports 39. on each side thereof. The disks 38 cause the strip l toimbed itself in the rolls 35, as shown in an exaggerated manner in Fig.8, so that the side edges of the strip, as Well as the bottom surface,receive a coating of liquid asphaltum.

After being treated with the acid resist, the strip is subjected toheat. The heating apparatus is shown more particularly in Figs. 9 and10, and comprises inclined guides 4l! having a gas Yburner 4I mountedthereon and held in positions of adjustments by engagement of the links42 with rack teeth 43. The burner 4! has a plurality of nozzles 44 whichmay be controlled independently by valves 55. The burner is of the Wellknown type embodying a pilot light, using compressed air, and a remotecontrol for the gas fuel so that the flames of the several burners maybe simultaneously controlled. That is, the burner may be adjusted bymeans of the Valves 45 to place any desired number of nozzles inoperation at one time and when once placed in operation the group ofnozzles may be simultaneously controlled by regulating the gas supplyfrom. a remote point. The burner is supplied with compressed air throughthe pipe line 46 and with gas fuel through the pipe line 41.

As may be seen upon reference to Fig. 1G, the burner 4l may be adjustedto 'positions nearer or more remote from the strip l by sliding it uponthe guides 4D, and as the strip passes over the burner it is heated, thepowdered asphaltum is heated and the gasoline solvent of the liquidasphaltum is ignited and burned. In the event movement of the. strip lstops for any reason the gas supply to the burners is immediatelydiscontinued while the compressed air supply is continued. The strip isnot, therefore, subjected to heat While it is stationary and thecompressed air will blow out any flame resulting from cornbusn tion-ofthe asphaltum solvent.

Reverting again to Fig. l, the strip l passes from the burner, abovedescribed, and over a comparatively large roll 48 which is driventhrough a chain 49 by the motor I3. The strip thus begins its second runinverted, that is, with the face having the pattern of resist thereon onthe bottom. During this second run of the strip it is treated by etchingfluids contained in a plurality of etching tanks 50, 50a and 50h. Thereis no restriction as to the number of etching tanks, and although threetanks are here shown it will be understood that more than three or lessthan three may be used. In practice, it is found practical to employmore than three in most cases.

The acid tanks are identical in construction and one of the same isshown in detail in Figs. 2, 3 and 4, to which views reference is nowhad. Each acid tank comprises a receptacle 5D, rectangular in form andopen at the top. Rotatably supported in bearings 5l, mounted externallyof the receptacle 56, are shafts 52 having pulleys 53 on the endsthereof for the reception of a belt drive.

, Although the operating motors are not shown, it

will be understood that the shafts 52 are driven in the direction of thearrows. Mounted upon each of the shafts 52 are two wood disks 54 unitedby rigid members 55 which support combs 55. As may be seen uponreference to Fig. 3, the combs 56, instead of being radially disposed,are tipped forwardly in the direction of travel of the shafts and disks.

The cover for the acid tank 50 comprises an inverted box-like structure,the end walls 51 of which have slots 58 therein permitting the invertedstrip l to pass therethrough. The side walls 59 rest upon the bottom ofthe tank 50 to support the end walls slightly spaced above the same. Theshafts 52 are encased in rubber, as

designated at 50, and the openings in the side f Walls of the tank 50through which the shafts 52 extend are provided with rubber seals 62 and63. The seals 63 are interposed between the side Walls of the tank 5i!and the side Walls 59 of the cover.

The top wall 64 has an outlet pipe 65 for the acid fumes and an openingE6 with a hinged closure 61 having a transparency 68 therein. Centrallydisposed between the shafts 52 is a baffle 69.

An acid supply pipe 15 is connected to the main supply conduit 1l and isequipped with a manual control valve 12. An acid outlet pipe 13 ismounted in the bottom of the tank 50 and comprises a flexible conduit.'Ihe conduit 13 is connected to a hollow-fitting 14 having a vent pipe15 slidably received in a bracket 18 whereby it may be adjustedvertically. The fitting 14 is connected by a second flexible conduit 11to a main conduit 18. In operation, the acid flows by gravity throughthe conduit 13, fitting 1G and conduit 11 to the'main conduit 13, whenthe liquid level in the tank is higher than the tting 1&1. By placingthe fitting 14 in different positions of vertical adjustment the liquidlevel in the tank 50 may be regulated. The vent pipe 15 serves both as asupport for the fitting 14 and also as a vacuum break to preventsyphoning.

The means for regulating the liquid level is diagrammatically shown inFig. 1 and is generally designated by the numeral 19.

Referring now to Fig. 1, numerals and 8|, designate, respectively, acidreservoirs which are placed in a plane above the tanks 50, 50a, and 50hso that the acids may ow by gravity from the reservoirs to the tanks.The liquid level regulating outlet means 1@ of the tank 5i! is connectedto the acid reservoir 8l) by a main conduit 82 having a pump therein forcausing movement of the liquid from the tank v5l! to the reservoir. Amain conduit conveys liquid from the reservoir, by gravity iiow, to thetank 50. The reservoir 8| is connected by a main conduit 35 to theoutlets 19 of both tanks 50a and 50h, and through a valve controlledpipe line 86 to the outlet 19 of the tank 5D. A pump 81 is provided inthe conduit 85. A conduit 88 is connected with the reservoir 8l and withthe acid tanks 50a and 50h, and through a valve controlled by-pass 89 tothe. inlet of the acid tank 50.

The above described system of conduits makes it possible to place all ofthe tanks 50, 50a and 50h in communication with either reservoir, or toplace the reservoir 80 in communication with the tank 50 and thereservoir 8| in communication with the tanks 50a and 50h. In the latterinstance the reservoirs would contain different acids, for example, thereservoir 80 might contain an acid which provides a very eflicientetching action on a new surface while the tanks 50a. and 50h, throughwhich the strips subsequently pass, might contain acids which provide amore efficient etching apparatus once the surface layer of metal hasbeen penetrated.

' With the apparatus in operation, theshafts 52 are rotated continuouslyand the combs 56 successively dip into the acid and throw a fine sp-rayagainst the strip l. This function permits an overchanging action in thecontact of the acid with the strip withv a highly eicient, rapid etchingaction resulting.

The level of the liquid within the tank 50, which is controlled by thehereinbefore described liquid level regulator indicated generally inFig. 1 at T9, determines the depth to which the combs 5B dip into theliquid during rotation of the shafts 52 on which they are mounted, andthus determines the density of the acid spray thrown against the stripThe chemical reaction between the acid and the metal of strip results ina rise in temperature of the acid on the strip. I have found thetemperature to which the acid is raised on its contact with strip I ishigher when a low density, ne particle, spray is used than when asimilar spray of greater density is employed and that under thesecircumstances the etching effect of the acid is faster with a lowvdensity spray than with a' higher density spray. It is, of course, wellknown that the etching speed of acid on metals increases with risingtemperature and it is my present belief that the more rapid etchingaction secured in my machine with a low density spray is the result ofthe high temperature obtained by the small quantity of acid in Contactwith the strip and that by increasing the spray density a lgreater'cooling eiect is produced by the greater quantity of acid thrown ontothe strip. The continuous circulation of the acid from the tank to thereservoirs and from the latter by gravity to the tank tends to retard adecrease in the etching eiliclency of the acid contained within thecontaining water and having a rotatable element 93 therein for throwinga spray against the strip. A major portion of the etching acids areremoved by this water spray and the strip then passes through a tank 94containing a soda solution. In the tank 94 are mounted rotatableelements 95 which, upon rotation thereof, dip into the soda solution andthrow a spray against the strip.` Any acids remaining after the firstwashing function are neutralized by the soda. The strip then passesthrough a tank 96 and is again element 91 therein.

The strip, in continuing its movement from 'the washing tank 96, passesthrough a housing 98 containing a quantity of water. submerged in thewater in the tank 98 is a steam pipe 99 having outlets for dischargingsteam through the water into the housing 98. In this housing thetemperature of the strip is raised and it then passes into the housingto which a hot air blast is supplied through the conduit |0|. The h otair blast thoroughly dries the strip.

From the second run of the strip, which is completed with the hot airblast, the strip passes over a roller |02, of comparatively largediameter, and enters the third and final run. Both rolls 48 and |02 maybe idling rolls, that is, with no motive force applied to them otherthan the .friction of the strip as it passes over their peripheralsurfaces. These rolls are constructed of a relatively large size for thepurpose of reversing the direction of movement of the strip 'withoutsubjecting it to one or more turns of short radius which would be apt tocrack the resist thereon and to otherwise damage the metal. In thepresent apparatus, however, the rolls 48 and |02 act as driving rollsfor the strip and, as illustrated inv Fig. l, are provided with suitablesprockets and are driven through the chains 49 and |02a respectively,sprocket and gear reduction I2 by the electric motor I3. It will beunderstood that with such driving means, the rate of rotation of therolls 48 and |02 is synchronized with the normal speed of the strip.During the third run, the strip has its etched surface uppermost, and itpasses through a spray booth |03. The spray booth is shown moreparticularly in Fig. 5, and as there shownvhas outlets |04 and l 05 attop and bottom thereof. Although it is not here shown, it will beunderstood that the usual air circulating means will be provided ,towithdraw the spray fumes from thebooth through these outlets. Mounted inthe booth 03 is a support |06 upon which arernounted spray guns |01, theguns as shown, being of v the adjustable type known tothe art andavailpasses through the drying oven |08 and is provided with a secondcoating of lacquer inthe spray booth |09 through which it subsequentlypasses. The second lacquer enamel coating is dried in the oven ||0.

The next step performed by the apparatus is that of removing the resistfrom the strip. In removing the asphaltum resist, the strip is passedover a roller and downwardly under a roller i2 in a tank containinggasoline or other solvent for the resist. The roller ||2 is formed withasurface of soft fibrous material, such as felt, and as it rotates in adirection opposite to the movement of the strip in Contact therewith, itsubmerges the stripin the solvent in tank I I3.` The strip then passesupwardly and over a roller H4 from which it again extends downwardly toasecond gasoline tank and felt roller ||6. In its run between the roller||3 and the roller ||4 the strip passes between Scrapers I6, formed of abone-like material.` An alternative form of scraper which has been foundsuccessful comprises a plurality of parallel horizontally arrangedcylnder steel bars mounted vertically one above the other in the path ofmovement of the strip from the roller l I6 to the second roller H2, thestrip passing on opposite sides of successive bars and in contacttherewith. The strip is, in this manner, treated successively byimmersion in gasoline, rubbing with a soft, gasoline saturated roller,and scraped, and after a succession of such treatments, shown by way ofexample as four, the resist is entirely removed from the unetchedsurfaces of the strip and such unetched surfaces are exposed in theirnatural condition. The strip is then dried and polished.

The drying and polishing means comprises receptacles it? and H8containing loose sawdust and the strip i passes over rollers lili andunder rollers llil to contact with the sawdust. The strip is finallywound upon a spool or drum l2! which is rotated through a frictionaldriving connection 22 by a motor 223. The frictional driving connectionpermits slippage between the motor and drum to compensate for thevariation in speed which ordinarily would result from increasing thediameter of the roll of strip while rotating the drum at a constantspeed.

Although a specific embodiment of the invention has been illustrated anddescribed, it will be understood that various changes may be made withinthe scope of the appended claims without departing from the spirit ofthe invention, and

such changes are contemplated.

What I claim is:

l. The process of producing an etched metallic strip of greatly extendedlength which comprises moving a continuous strip of metal in alongitudinal direction and in the course of the movement repeatedlyapplying an ink design to one side of the strip, applying to said inkdesign a powdered material capable of forming an acid resist whenheated, applying a resist coating on the other side of the strip,applying a resist coating to the longitudinal edgesl of the strip,heating the strip, all of said steps being performed dur-i, ing movementof the strip, and subsequently subjecting the strip to an acid etchingtreatment.

2. A method of producing an etched metallic strip of greatly extendedlength which comprises, moving a continuous strip of metal in alongitudinal direction and in the course of such movement repeatedlyapplying designs in liquid to one side of the strip, applying to saiddesigns a powdered material capable of fusing and for.. ing a resistwhen heated, removing excess powdered material from the strip, applyingan acid resist coating to the other sido of the strip, heating r thestrip, subjecting the strip to an acid etching treatment, subjecting thestrip to a cooling iiuid, subjecting the strip to a saline solution toclean the strip, and then subjecting the strip to a water spray toremove the saline solution, all of said steps being performed duringmovement of the strip 3. A method of producing an etched metallic stripof greatly extended length which comprises, moving a continuous strip ofmetal in a longitudinal direction and in the course of such movementrepeatedly aplying designs in liquid to one side of the strip, applyingto said designs' a powdered material capable of fusing and forming aresist when heated, removing excess powdered material from the strip,applying an acid resist coating to the other side of the strip, heatingthe strip, subjecting the strip to an acid etching treatment, subjectingthe strip to a -cooling fluid, subjecting the strip to a saline solutionto clean the strip, then subjecting the strip to a water spray to removethe saline solution, subjecting the strip to a heated liquid, and thensubjecting the strip to an air blast to dry the same, all of said stepsbeing-performed during movement lof the strip. l

4. A method of producing an etched metallic strip of greatly extendedlength which comprises, moving a continuous strip of metal in alongitudinal direction and in the course of such movement repeatedlyapplying designs in liquid to one side of the strip, applying to saiddesigns a powdered material capable of fusing and forming a resist whenheated, removing excess powdered material from the strip, applying anacid resist coating to the other side of the strip, heating the strip,subjecting the strip to an acid etching treatment, subjecting the stripto a cooling fluid, subjecting the strip to a saline solution to cleanthe strip, subjecting the strip to a water spray to remove the salinesolution, subjecting the strip to a heated liquid, subjecting the stripto an air blast to dry the same, spraying enamel on the strip and thenheating the strip to rapidly dry the enamel, all of said steps beingperformed during movement of the strip.

5. A method of producing an'etched metallic strip of greatly extendedlength which comprises, moving a continuous strip of metal in alongitudinal direction and in the course of such movement repeatedlyapplying designs in liquid to one side of the strip, applying to saiddesigns a powdered material capable of fusing and Yforming a resist whenheated, removing excess powdered material from the strip, applying anacid resist coating to the other side of the strip, heating the .u

strip, subjecting the strip to an acid etching treatment, subjecting thestrip to a cooling fluid, subjecting the strip to a saline Solution toclean the strip, subjecting the strip to a water sprayto remove thesaline solution, subjecting the strip to a heated liquid, subjecting thestrip to anl air blast to dry the same, spraying enamel on the strip,heating the strip to rapidly dry the enamel, subjecting the strip to alacquer spray, and then heating the strip to rapidly dry the lacquer,all of said steps being performed during movement of the strip.

5. The method of providing strip metal with ornamental designs orindicia which consists in providing a pattern on the strip with amaterial having aflinity for powdered acid resist, dusting a fusibleacid resist of powdered form on the patterned portions of said strip,coating the rear and side edges of the strip with an acid resist held bya combustible solvent, and subjecting the strip to a flame to ignite aidsolvent whereby combustion thereof supplies at least a part of the heatfor fusing the powdered acid resist.

'7. A method of producing an etched metallic strip which comprises,moving a continuous strip of metal longitudinally thereof and duringsuch movement repeatedly by applying designs in liquid to one side ofthe strip, applying to said liquid designs a powdered material capableof fusing with the liquid when heated to provide a resist to etchingliquid, heating the strip to fuse the powdered material and liquid intoa resist, subjecting the strip to an etching liquid, cooling the strip,cleaning the strip with a cleaning substance, and then removing thecleaning substance frcm the strip, all of said steps being performedduring movement of the strip.

8. A method of producing a continuous etched strip which comprisesmoving the strip longitudinally thereof and during such movement repeatedly applying designs in liquid on one side of the strip, applyingto said liquid designs a powdered material adapted to fuse with theliquid when heated to form an etching acid resist, removing excesspowdered material rom the metallic strip, applying an etching acidresist to the other side of the metallic strip and simultaneouslytherewith applying acid resist to the longitudinal edges of the strip,heating the strip, passing the strip through an etching acid bath,passing the strip through a cooling liquid bath, passing the stripthrough a cleansing liquid bath, passing the strip through a heatedliquid bath, subjecting the strip to a hot air blast,fenameling thestrip, baking the enamel into the strip, applying asphaltum solvent tothe strip and finally drying the strip.

DONALD A. MARSHALL.

